1. Field of the Invention
The present invention relates to a sealing member in the form of a plate for a connection piece or a similar connection part for a conduit for liquid or gas on a container.
2. The Prior Art
In pressurized water reactors (nuclear power reactors) the steam generator and the reactor vessel are connected to each other in the primary circuit of the reactor. The connection between the steam generator and the reactor vessel normally comprises a connection piece in the form of a nozzle arranged on the steam generator. In connection with maintenance and repair of the steam generator it is of the utmost importance that the nozzle can be effectively sealed so that the reactor vessel is not contaminated by decontamination liquid, washing water, or by solid contaminating materials associated with the cleaning of the steam generator which is then necessary. By sealing the nozzle, emptying of the primary circuit when the above-mentioned operations are to be carried out can also be avoided.
Achieving an efficient sealing of the nozzle on the steam generator constitutes a considerable problem, since the nozzle is not directly accessible from outside. For the sealing of the nozzle it is necessary to employ the manhole of the steam generator, which has a considerably smaller diameter than the nozzle.
From European patent application EP No. 0 121 172 it is known to accomplish the sealing by a foldable plate, which in folded state is passed into the steam generator via the manhole and which is unfolded inside the steam generator. The known plate comprises a number of sheet metal elements of a shape resembling a U-beam, which are arranged adjacent to each other and are interconnected by hinges, in the upper parts of branch parts of the sheet elements making contact with each other.